If idling stop is executed while an air conditioner is in operation for cooling or dehumidification in a passenger compartment of a vehicle, a compressor stops along with the stop of the engine. In some cases, therefore, outlet temperature of air-conditioned air increases, which provides a feeling of discomfort to occupants, or the dehumidification performance of the air conditioner is reduced, which causes fog on windows.
Japanese Patent Application Publication No. 2000-289454 discloses an idling stop control unit capable of preventing the aforementioned feeling of discomfort or occurrence of fog on windows. According to the above-described idling stop control unit, an idling stop switch which is manually operated by an occupant is provided with an off switch for prohibiting idling stop, and the occupant operates this off switch to prohibit the idling stop.